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Study on Lubricating Properties of Emulsions in EHL Contacts

In this study, a model has been developed for the elastohydrodynamic lubrication with binary mixtures of compressible fluids, which can be used to represent emulsions with suspended deformable particles. The coupled modified Reynolds, elasticity, and rheology equations are solved simultaneously by combining the advanced multilevel method and the Newton-Raphson method. The effects of speed, load, dimensionlesss materials parameter, inlet oil volume fraction, droplet radius, surface tension group, elasticity of mixture, and equivalent viscosity models of emulsions on the lubrication characteristics of the emulsions are investigated.
The speed, load, and oil volume fraction combinations studied in this study represent a broad range of operating conditions previously not investigated. The results of this study are in good agreement with the tests conducted by Kimura et al. and Zhu et al. indicating the effects of droplet radius of oil phase and the speed on the film thickness. The film thickness increases with increasing droplet size for the droplet size smaller than the film thickness. At the low oil volume fraction and low speed, the oil volume fraction increases rapidly with coordinate x to form the oil pool in the region close to the Hertzian contact area. With the increase of speed, the extent of the oil pool decreases significantly so that the oil volume fraction at the contact area decreases rapidly. Consequently, the film thickness also decreases due to the decrease in the effective viscosity of the mixture. When the speed is getting higher, the oil and water phases enter the contact conjunction so that the oil volume fraction is closer to the inlet one.

Identiferoai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0907108-153123
Date07 September 2008
CreatorsWang, Tsung-hsien
ContributorsYuang-Cherng Chiou, Yeau-Ren Jeng, Jen-Fin Lin, Rong-Tsong Lee
PublisherNSYSU
Source SetsNSYSU Electronic Thesis and Dissertation Archive
LanguageCholon
Detected LanguageEnglish
Typetext
Formatapplication/pdf
Sourcehttp://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0907108-153123
Rightsunrestricted, Copyright information available at source archive

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